Answer:
see below
Explanation:
16. 1 P₄(s) + 6 F₂(g) → 1 PF₃(s)
17. 2 C(s) + 2 H₂O(g) → 1 CH₄(g) + 1 CO₂(g)
18. 2 HgO(s)→ 1 O₂(g) + 2 Hg(l)
19. 1 CaCO₃(s) → 1 CO₂(g) + 1 CaO(s)
With newly discovered materials, nothing is yet know about them. Scientists don't know how to conduct physical/chemical experiments without damaging the element. Lethal substances or corrosive materials can be set off from combustion or decomposition. It would be difficult to determine the properties because no one knows what the element is made of. Chemical properties are often characterized by <span>reactivity with other chemicals, such as toxicity, coordination number, flammability, enthalpy of formation, the heat of combustion, and <span>oxidation states. It is difficult to measure those things when you have no idea what an element may be giving off. </span></span>
Answer:Ionic compounds form when positive and negative ions share electrons and form an ionic bond. ... The positive ion, called a cation, is listed first in an ionic compound formula, followed by the negative ion, called an anion. A balanced formula has a neutral electrical charge or net charge of zero.
Explanation:Simple ions:
Perchlorate ClO4- IO3-
Chlorate ClO3- BrO3-
Chlorite ClO2-
Hypochlorite OCl- OBr-
The electrons always orbit around the nucleus, forming what is called an electron cloud. :)